1. Field of the Invention
This invention relates to the design of a pull handle for a wheeled suitcase, and more particularly, to a tilt-locking pull handle which is locked when the wheeled suitcase is tilted for moving, and unlocked when the wheeled suitcase is repositioned to an upright position.
2. Description of the Prior Art
Wheeled suitcases are popular for traveling because they can easily be pulled rather than carried. A slidable pull handle is commonly used in many wheeled suitcases to facilitate the pulling or pushing of a wheeled suitcase. In order to use such slidable pull handle, a user must pull the pull handle first to an utmost position, and then tilt the wheeled suitcase toward its rear end for moving.
Conventional pull handles usually comprise at least one slidable rod member on its lower end which is slidably engaged in a rod receiving means installed on the rear side of a wheeled suitcase. The pull handle must be maintained in its utmost position when pulling or pushing a wheeled suitcase. If the slidable pull handle can not be fixed in its utmost position, it can cause great difficulty in moving the wheeled suitcase because the pulling or pushing of the wheeled suitcase may become uncontrollable.
In order to maintain the rod member in its utmost position, two types of mechanical devices are usually used inside a rod receiving means for fixing the rod member. The first type of mechanical device is a rod detention which can temporarily confine the lower end of the rod member in the utmost position of the rod receiving means. The lower end of the rod member can pass through the rod detention by a forceful pull or push action when it reaches the rod detention. The rod detention can resist certain pushing forces from the top of a pull handle when its rod member is confined at the utmost position. But when such wheeled suitcase is pushed through an uneven surface or maneuvered unevenly, the rod detention can easily be forced through by the rod member and thus may cause a lot of inconveniences in moving such wheeled suitcase.
The second type of mechanical device is a manual locking device which can reliably lock a slidable rod member at its utmost position. Since the on and off of the manual locking device is controlled by a manual switch, frequent access of the manual switch may become necessary when maneuvering such wheeled luggage, and thus may cause some inconvenience. Besides, the manual switch itself may increase the complexity and cost of the wheeled luggage.